Toyota Tundra Service Manual: Lost Communication with ECM / PCM "A" (U0100,U0122)

DESCRIPTION

This DTC is detected if communication is lost between the ECM and skid control ECU.

CAUTION / NOTICE / HINT

NOTICE:

• When the data in the ECM or skid control ECU is being overwritten, the indicator light may rapidly blink due to the 4 wheel drive control ECU detecting a communication malfunction (blinks at 0.25 second intervals (0.25 seconds on and 0.25 seconds off)), but this is not a malfunction.
• Clear all DTCs, since DTCs are stored after the data in the ECM or skid control ECU is overwritten.

PROCEDURE

(a) Clear the DTCs (See page ).

(b) Check if the same DTCs are output (See page ).

A

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

B

USE SIMULATION METHOD TO CHECK